In a variety of semiconductor power applications, insulated gate field effect transistors (IGFETs), for example metal oxide semiconductor field effect transistors (MOSFETs) are used to switch electric loads on and off. Transistor cell concepts including gate electrode and gate dielectric in trenches may allow for a reduction of an area-specific on-resistance (Ron×A) due to higher packing density of the transistor cells compared with planar cell concepts. By further accommodating one or more field electrodes or field plates in the trenches a trade-off relationship between breakdown voltage and on-resistance may be further improved. Charge compensation by the field plates in an edge termination area may interact with an electric field distribution due to an edge termination construction of the body region. The interaction may limit a breakdown voltage margin of the device.
Hence, it is desirable to further improve the trade-off relationship between breakdown voltage and on-resistance in field plate trench IGFETs.